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Java > Open Source Codes > com > lutris > util > PersistentStore


1
2 /*
3  * Enhydra Java Application Server Project
4  *
5  * The contents of this file are subject to the Enhydra Public License
6  * Version 1.1 (the "License"); you may not use this file except in
7  * compliance with the License. You may obtain a copy of the License on
8  * the Enhydra web site ( http://www.enhydra.org/ ).
9  *
10  * Software distributed under the License is distributed on an "AS IS"
11  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
12  * the License for the specific terms governing rights and limitations
13  * under the License.
14  *
15  * The Initial Developer of the Enhydra Application Server is Lutris
16  * Technologies, Inc. The Enhydra Application Server and portions created
17  * by Lutris Technologies, Inc. are Copyright Lutris Technologies, Inc.
18  * All Rights Reserved.
19  *
20  * Contributor(s):
21  *
22  * $Id: PersistentStore.java,v 1.1 2005/07/13 11:09:06 slobodan Exp $
23  */
24
25
26
27
28
29 package com.lutris.util;
30 import java.io.Serializable JavaDoc;
31
32 /**
33  * Persitent storage interface.
34  *
35  * @author Kyle Clark
36  */
37 public interface PersistentStore {
38
39     /**
40      * Method to store and object (persistent).
41      *
42      * @param key The key by which to identify the stored object.
43      * @param obj The serializable object to store.
44      * @exception com.lutris.util.PersistentStoreException
45      * if an error occurs.
46      */
47     public void store(String JavaDoc key, Serializable JavaDoc obj)
48         throws com.lutris.util.PersistentStoreException;
49
50     /**
51      * Method to retrieve a stored object.
52      *
53      * @param key The key of the user whose session
54      * is to be retreived.
55      * @return The stored object. If an object is not
56      * stored under key, then <code>null</code> is returned.
57      * @see #remove
58      * @exception com.lutris.util.PersistentStoreException
59      * if an error occurs.
60      */
61     public Object JavaDoc retrieve(String JavaDoc key)
62         throws com.lutris.util.PersistentStoreException;
63
64     /**
65      * Method to simultaneously retrieve and remove an
66      * object from persistent store. If an object is not
67      * stored under key, then null is returned.
68      *
69      * @param key The key by which to identify the stored object
70      * that is to be removed.
71      * @return The object that has been removed.
72      * @exception com.lutris.util.PersistentStoreException
73      * if an error occurs.
74      */
75     public Object JavaDoc remove(String JavaDoc key)
76         throws com.lutris.util.PersistentStoreException;
77
78     /**
79      * Method to delete a a key. Any objects stored under
80      * key are also removed. If key is not defined, then
81      * this method does nothing.
82      *
83      * @param key
84      * The key to remove.
85      * @exception com.lutris.util.PersistentStoreException
86      * if an error occurs.
87      */
88     public void delete(String JavaDoc key)
89         throws com.lutris.util.PersistentStoreException;
90
91
92     /**
93      * Method to query if an an object is stored.
94      *
95      * @param key The key by which to identify the stored object.
96      * @exception com.lutris.util.PersistentStoreException
97      * if an error occurs.
98      */
99     public boolean exists(String JavaDoc key)
100         throws com.lutris.util.PersistentStoreException;
101
102
103     /**
104      * Method that returns an enumration of the keys
105      * of this persistent store.
106      *
107      * @exception com.lutris.util.PersistentStoreException
108      * if the enumeration could not be determined.
109      */
110     public java.util.Enumeration JavaDoc keys()
111         throws com.lutris.util.PersistentStoreException;
112
113
114 }
115
116
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